The Gribshunden, or Griffen, the flagship of King John of Denmark, sank in 1495 off the coast of Ronneby, southeastern Sweden, while on the way for talks with Swedish separatist forces int he city of Kalmar.
“It's what we would expect but I still think it's quite fun because it gives us an insight to the life on board,” Johan Rönnby, an archeologist from Södertörn University outside Stockholm, told The Local.
“We haven't taken any samples, so we can't 100 percent say that it is beer, but it is most likely that it would be beer on a ship, as water was not that healthy to drink.”
The suspected beer barrels are marked with the letter 'A' and fitted with two stoppers on the lid, which would have enabled easy pouring.
Rönnby's colleague Brendan Foley, a researcher from Lund University, said that the team were currently taking samples from the barrels to determine their contents.
“We're taking sediment samples now and hoping we're going to find DNA evidence of hops,” he said.
“What we're doing is getting a look at not just what the men on the ship were drinking but what King John was taking to Kalmar to impress Sten Sture the Elder.”
Sten Sture the Elder had led Swedish separatist forces to victory against royal unionist forces at the Battle of Brunkeberg in 1471, after which he had become effective ruler of Sweden.
The excavation of the Gribshunden, which is being part-funded by the Lund-based Crafoord Foundation, involves 40 researchers from 10 countries.
The researchers announced the discovery with a press release on Friday.